NASA will announce on Thursday, July 31, the instruments that will be carried aboard the agency’s Mars 2020 mission, a roving laboratory based on the highly successful Curiosity rover. The announcement will air live at noon EDT on NASA Television and on the agency’s website.

NASA received 58 proposals in January for science and exploration technology instruments to fly onboard the Mars 2020 mission, two times the average number of proposals submitted for instrument competitions in the recent past and an indicator of the extraordinary interest in exploration of the Red P...